Papers by Author: Qin Xu

Abstract: Silicon nitride ceramics materials have excellent properties such as small density, high rigidity, high Young's modulus, high wearability, good thermal stability and chemical stability, which make it become one of the most appropriate materials for rollers of high precision bearing. Chemical Mechanical Polishing (CMP) technology is employed to have an ultra-precision machining process for silicon nitride ceramics materials workpiece and the effects of workpiece surface roughness in different abrasive are discussed in this research. The XRD and SEM technology are used to take phase analysis and surface profile detection for the finishing workpiece polished with CeO2 abrasive. The chemical reaction mechanism and the material remove mechanism of silicon nitride ceramics materials in CMP process with CeO2 abrasive are both analysed and discussed in this paper. The research result shows that an extremely smooth surface of silicon nitride ceramics materials workpiece with roughness 5nm Ra is obtained after CMP process with polyurethane polishing pad and CeO2 abrasive.

Abstract: To obtain the amorphous alloy films with superior properties by method of electrochemical deposition, the accuracy requirement for the copper substrates for Alloy Films is extraordinarily strict. The ultraprecision lapping technology for the copper substrate employing polyurethane polishing pad and flannel pad is studied in this paper, surface roughness, material removal rate and change process of surface construction of copper substrates are discussed. The influences of the different lapping parameters on the surface roughness, material removal rate and the influences of lapping load on copper substrate surface formation in the ultraprecision lapping process of copper substrate are both discussed. Experiment results show that the surface scratch will disappear by employing polyurethane polishing pad and flannel pad, and an extremely smooth surface of copper substrate with roughness 6nm Ra is obtained in the final finishing lapping process.